Various systems are known for using curb construction for inserting skylights and smoke vents into roofs.
The most commonly used skylighting systems are those that incorporate translucent or transparent layers in a framework that penetrates the roof structure, so as to allow ambient daylight into the building.
In the past roof penetrating installations have required a complex structure beneath the roofing panels in order to support a roof curb to which the skylight was attached. Skylight curbs are generally in the form of a preassembled box structure, that is fixed within a roof cutout. The retrofitting of such curb systems into existing roof structure is problematic.
U.S. Pat. No. 4,296,581, to Heckelsberg, issued Oct. 27, 1981, provides an example of a roofing structure of the type that is constructed of a series of metal panels having flanges that interlock when the panels are laid side by side and which are subsequently tightly seamed together to convert the individual panels into an integrated roof forming membrane. This roof structure is mounted to the purlins with clips that permit the panels to expand or contract in response to temperature and pressure changes, thereby minimizing roof stressing.
U.S. Pat. No. 4,703,596, to Sandow, issued Nov. 3, 1987, and titled “Grid Skylight System”, provides a grid skylight support apparatus that includes prefabricated grid row frames, each of which form a number of connected beam supports which define a number of bays. Each bay has a skylight curb formed by upper flanges of the beam supports to receive a preassembled skylight unit. The sides of each grid row frame provide a mating edge that can register with the mating edge of an adjacent grid row frame during assembly. The skylights have peripheral support skirts that register upon each bay and a light-transmitting skylight panel to cover the peripheral support. Cross gutters on each grid row frame, which are positioned between adjacent skylights, extend at an angle toward the mating edge of the grid row frame for carrying rainwater to a main gutter channel formed by field-assembly of the mating edges of two adjacent grid row frames. The main gutter channel includes a pair of longitudinally extending gutter sections, each of which have a main gutter channel surface with a lower elevation than the elevation of the cross flow channel. Fasteners assemble the grid row frame mating edges together and a continuous seal to prevent rainwater leakage at the mating edges of adjacent grid row frames.
U.S. Pat. No. 4,520,604, to Halsey et al., issued Jun. 4, 1985, entitled “Skylight Structure”, teaches a curb structure that is dimensioned to be passed through an opening in a roof and then attached in moisture impervious relation to the roof from within a building interior. A skylight assembly including a frame and light transmitting member secured to the frame is dimensioned to be passed through the opening and attached in a sealing engagement to the curb structure from within the building interior for covering the opening. The skylight assembly is then secured to the rafters and headers at an interior location. The frame includes upper and lower clamping jaws and spaced fulcrum links attached to the jaws for clamping the light transmitting member thereto. The lower clamping jaw includes a channel which engages and is interlocked with the curb structure.
Other skylight systems, as contemplated in U.S. Pat. No. 4,470,230, by Weinser, provide a prefabricated skylight support curb that is formed to be a protective packaging for the skylight during shipment and then used as a curb for mounting the skylight on a roof. A prefabricated skylight support curb for supporting a skylight thereover has a bottom flange angled, upright sides, and a top lip round the top of the sides forming an opening through the curb. A skylight is adapted to cover the opening through the skylight support curb when installed, and has a domed portion and an angled portion extending from the dome portion and a drip edge on the curb portion. The skylight curb portion is shaped to fit over a portion of the prefabricated skylight support curb angled upright portion and top lip. The skylight support curb is shaped to nest an accompanying skylight therein having the skylight curb portion adjacent to the interior of the skylight support curb angled upright walls to protect the skylight during shipping and storing.
In another skylight system, as contemplated in U.S. Pat. No. 3,791,088, by Sandow et al., a prefabricated multiple dome unit or skylights and composite is provided, wherein each multiple dome unit has several domes of transparent or translucent material mounted together on a common frame, and wherein means are provided for assembling a plurality of such dome units into a composite thereof on a building, with the units lapped and interfitted so as to provide a continuous drainage system discharging to the exterior of the units in the composite assembly.
In yet another skylight system, as contemplated in U.S. Pat. No. 4,642,466, by Sanneborn et al., a flashing frame is described for roof windows to be installed adjacent to each other with edges facing each other in the installed position with a connecting flange of its upper flashing members extending beneath the roofing and, if need be, with its lower flashing members and required intermediary flashing members, obliquely outwardly bent connecting webs and each with a connecting bar with supporting webs which rearwardly engage the connecting webs being adjacent to the width of the installation distance and are obliquely bent inwardly on both sides, and at least one inner projection which engages between the facing corner edges of the connecting webs in the installed position, thus maintaining these corner edges at the installation distance.
In today's world of mandated energy efficiency in all types of buildings the metal building industry needs a more economical and less detrimental way to use skylights and smoke vents to daylight their buildings. To ensure adequate daylighting, however, typical skylight and smoke vent installations require multiple roof penetrations that cut through and remove plural major elevations in standing seam and other roof panel profiles. These curbs create multiple opportunities for water to enter the interior of the building, due to multiple curb locations and the width of the curbs, as well as the challenge to effectively seal the roof at the high end of such curbs.
The traditional curb constructions and methods of attachment in most cases require a complicated support structure to be installed below the roof panel which can restrict movement associated with the thermal expansion and contraction of the metal roof due to temperature changes and the like.
None of the prior approaches have been able to provide an installation system for multiple skylights that accomplishes all the goals of economy and simplicity of installation and will work equally well for new buildings and as a retrofit in existing buildings.